Machine for making precast concrete products



July 27, 1965 PARMA MACHINE FOP. MAKING PRECAST CONCRETE PRODUCTS '7 Sheets-Sheet 1 Filed Feb. 11, 1963 INVENTOR.

PA R MA 001M411: lco

July 27, 1965 D. PARMA 3,196,513

MACHINE FOR MAKING PRECAST CONCRETE PRODUCTS Filed Feb. 11, 1963 '7 Sheets-Sheet 2 INVENTOR. D OMEN/c o PARMA ATTYS.

July 27, 1965 D. PARMA MACHINE FOR MAKING PRECAST CONCRETE PRODUCTS 7 Sheets-Sheet 5 Filed Feb. 11, 1963 ATTYa.

July 27, 1965 D. PARMA MACHINE FOR MAKING PRECASI' CONCRETE PRODUCTS Filed Feb. 11, 1963 '7 Sheets-Sheet 4 III 48 I ,llHh 1 INVENTOR.

PA R MA Domsmco July 27, 1965 D. PARMA 3,196,513

MACHINE FOR MAKING PRECAST CONCRETE PRODUCTS Filed Feb. 11, 1963 7 Sheets-Sheet 5 Fla. 6

1 INVENTOR. D oMe/wco PAR MA July 27, 1965 D. PARMA 3,196,513

MACHINE FOR MAKING PRECAST COIfXCRETE PRODUCTS Filed Feb. 11, 1963 I. 7 sheets-sheet 6 di I :r INVENTOR. DOMEN/CO PARMA 01N332 0 WM Jul 27, 1965 D. PARMA 3,

MACHINEFOR MAKING PRECAST CONCRETE PRODUCTS Fna Feb. 11, 1963 7 Sheets-Sheet 7 INVENTOR.

PA R MA ATTYS.

DOMEN/(O United States Patent 3,196,513 MACHINE FGR MAKENG PRECAST CONCRETE PRQDUCTS Domenico Par-ma, Carrera 72: No. 17-61, Uficina No. 365, Bogota, Colombia Filed Feb. 11, 1963, Ser. No. 257,723 7 Claims. (Cl. 25-41) This invention relates to a new and improved machine for making precast concrete products, such as blocks, boxes, slabs and the like.

One object of the present invention is to provide a new and improved machine which is especially well adapted for making precast concrete boxes, each of which will have a thin lower wall or web and thin side walls or flanges projecting generally at right angles therefrom. Such boxes are extremely useful in the construction of floor slabs or other structures made of reinforced or pre stressed concrete. In such structures, the boxes are stacked in pairs and are employed to form voids in the structure. A further object is to provide a new and improved machine having means whereby the hollow box-like block is molded in an inverted position and then is turned over and discharged from the machine, on a supporting pallet, in an upright position.

Another object is to provide a new and improved ma chine which is arranged so that the entire machine may be wheeled away from a newly molded block into a new position in which another block may be molded and discharged onto the floor under the machine.

It is a further object of the invention to provide a new and improved machine of the foregoing character which is effective and speedy in operation, yet is remarkably simple in construction and low in cost.

Further objects and advantages of the present invention will appear from the following description, taken with the accompanying drawings, in which:

FIG. 1 is' a perspective view of a machine for making concrete products, to be described as an illustrative embodLnent of the present invention.

FIG. 2 is a perspective view of a concrete box which may be molded by the machine of FIG. 1.

FIG. 3 is a somewhat diagrammatic vertical cross section taken through the machine and showing the machine in its initial condition, before the molding of the block has been started.

FIG. 4 is a view similar to FIG. 3, but showing the the machine with its mold filled with a charge of wet concrete.

FIG. 5 is a view similar to FIG. 4, but showing the machine in the position in which the concrete in the mold is pressed and compacted so as to form the molded block.

FIG. 6 is a view similar to FIG. 5, but showing the manner in which a supporting pallet is mounted on the mold after the pressing and compacting operation has been completed.

FIG. 7 is a view similar to FIG. 6, but showing the manner in which the mold and the block therein are inverted, preparatory to discharging the block from the machine.

FIG. 8 is a view similar to FIG. 7, but showing the machine in its final position, after the block or box has been discharged from the mold and deposited with its supportingpallet on the floor, under the machine.

FIGS; 9 and 10 are perspective views of other types of concrete blocks or boxes which may be molded on the machine, by suitably modifying the mold structure.

It Will be seen that the drawings illustrate a machine 12 which may be employed for molding concrete products, such as blocks, boxes, slabs or the like. FIG. 2 illustrates a concrete product 20 which may be molded to great advantage on the machine 12 of FIG. 1. As shown, the concrete product 21) is in the form of a square or rectangular box, having a thin horizontal bottom wall or web 22, together with thin side walls 24 projecting upwardly therefrom. The walls 22 and 24' define a hollow space or cavity 26 within the box 20.

Boxes of the type shown in FIG. 2 are particularly useful in making various types of floor slabs or! other structures, made of reinforced or prestressed concrete. The boxes or blocks 20 are usually employed in pairs, one stacked upon the other, with the upper block inverted so that the cavities 26 in the two blocks are opposite each other to form an enclosed hollow space. The pairs of blocks are employed to form. voids in the concrete slab so as to reduce the weight of the slab and the amount of material employed therein. FIGS. 9 and 10 illustrate other blocks 28 and 29 which may be molded by the machine of FIG. 1, by suitably modifying the mold structure. It will be understood that a Wide range of concrete products may be molded with the machine of the present invention.

The machine 12 of FIG. 1 has a main frame 30 which comprises two rectangular side frames 31 and 32 hav-' ing bars 33 extending therebetween. Four wheels 34 are mounted on the main frame 39, two wheels being mounted on each side frame 31. Thus, the entire machine may readily be rolled along. the floor from one position to another.

The main frame 30 supports a rotatable subframe 40 which in turn supports a mold 42 in which the concrete blocks or boxes are formed. Axles or pivots 44 and 46 extend laterally in opposite directions from the subframe 40 and are rotatably supportedby bearings 48 and 49, mounted on the side frames 31 and 32. Thus, the entire subframe 40, including the mold 42', is rotatable between upright and inverted positions.

Any suitable means may be employed for rotating the subframe 40. In the illustrated construction, a gear or pinion 59 is mounted on the axle 46. Thepinion 50 meshes with a rack 52 which is. adapted to be reciprocated by a fluid power cylinder 54. It will be understood that the cylinder 54 may be actuated by any suitable pres sure fiuid, such as compressed air or hydraulic fiuid un der pressure.

As shown, the mold 42 comprises an interior mold part 69 and an exterior mold part 62. It will be understood that the mold parts 60 and 62 correspond in shape to the desired interior and exterior shape of the block or box to be molded. Thus, the interior mold 6% is rectangular or square in shape and is formed with four sloping or tapering walls 64. A horizontal lid or plate 66 is loosely supported on the upper end of the interior mold 60 as shown in "FIG. 3. The lateral position of the lid 66 is maintained by pins or bolts 68 and 69 which extend through apertured lugs 70 on the side walls 64. The pins 68 and 6d are slidable through the lugs 70. Heads 71 and 72 are provided on the pins 68 to limit the movement of the lid 66 away from the interior mold 60. Thepins 69 are the same as the pins 68 exceptthat the pins 69 are somewhat longer than the pins 68, so that the pins 68' restrict the movement of one'side portion of the lid 66 to a greater extent than the other side of the lid is restricted by the pins 69'.

As shown, the exterior mold 62 issquare or. rectangular in shape and is formed with substantially vertical side walls 74. The interior mold 60 is connected to the ro tatable subframe 40 by means of coil springs 76. One end of each spring 76 is secured to-the subframe 40, while the other end is secured to a lug or bracket 78 on the interiormold Four of these springs 76 may be em- I ployed. The springs 76 are preferably rather stiff, but they do permit vibratory movement of the interior mold 60 relative. to the subframe 40. a a

The exterior mold 62 is also connected to the subframe 40 by means of springs 80 which are shown as compression coil spring acting between the subframe: 40* and lugs or brackets 82 on the exterior frame 62. The extension of each spring 80 is limited by a stop rod 84 extending axially through the spring. One end of each rod 84 is secured to the subframe 40,1while the other end is slidable through an aperture in the corresponding lug 82. The rod 84 is formed with a head 86 which is engageable with the lug 82 to limit the extension of the spring 80.

The interior and exterior molds 60 and 62 form a mold cavity 90 which corresponds in shape to the box or block to be'molded. The bottom of the mold cavity is formed by a rectangular frame 92 which fits between the lower ends of the interior and exterior molds, 60 and 62. The frame 92 is loosely mounted'so that it may be employed to eject the finished block from the mold 42. In its initial position, the frame 92 is supported by a plurality of lugs or brackets 96, which are mounted on the exterior frame 62' and extend under the lower edge of the exterior frame. The lugs 96 are engageable withthe lower sideo'f the rectangular frame 92 so as to prevent theframe 92 from moving downwardly below the lower edge of the exterior mold62LJ j The ejectorframe 92 is adapted to be operated by an ejector mechanism 100 comprising a hydraulic or pneumatic cylinder or ,jack' 102 mounted on the subframe 40 under the'interior mold 60. A piston 104 is slidable in the'cylinder 102 and is connected to a piston rod 106. The outer end of the piston rod 106 is pivotally connected to a cross bar 108.' A plurality of guide rods 110' are connected to the outer ends of the cross bar 108. It will brackets 116on the upper'ends of the guide'rods'110.

The springs 112 are given an initial tension so that they bias the guide rods 110 and the cross bar 108 downwardly.

A plurality of rods 120 are connected to the ejector frame 92 and extend downwardly therefrom. The lower ends of the rods 120 are pivotally connected to a cross slidable in the cylinder 146 and is connected to the plate 144 by means of a piston rod 152. A plurality of return springs 154 are connected between the plate Y144 and the trolley frame 148.

It will be seen that the trolley frame 148 is mounted between sets of rollers 156 which are rotatably mounted on supporting members 158 secured to the main frame 30.

After the mold 62 has been filled with its charge of concrete 140, the trolley frame148 is moved along the rollers 156 so as to move the press plate 144 over the mold 42, as shown in FIG. 5. To resist the force of the'hydraulic jack 146, the left-hand end of the trolley frame 148 is moved under hooks or lugs'160-which are formed on members 162 extending upwardly from the main frame 30.

The actuation of the fluid jack 146 presses the plate 144-against the upper end of the. exterior mold 62 so as to compress the concrete 140 in the mold 42.. The illustrated plate 144 is provided with laterally extending wings or portions 164 which areengageable with'the bars or brackets 166'on the upper'ends of the guide rods 110 so as to press the guide rods 110 downwardly. Through the linkages 124 and the rods 120, the ejector frame 92 is pulled downwardly and thus is maintained against the lugs 96 on the exterior frame 62.

The mold 42 is preferably equippedwith a poweractuator vibrator 170 which is mounted on the interior mold 60. When: the press plate 144 has been moved against the top of the exterior mold 162, the vibrator 170 is started so as to compact the concrete 140. It will be understood that the concrete is compactedby the combined vibratory'action of the vibrator 1 70. and compresv sive action of the press plate 144.

The pressure developed by the press plate 144 may press theexterior mold 62-downwardly relative to the interior mold 60. However, the ejector frame 92 moves downwardly with theexterior mold 62, due to the tension in the rods 120, so thatthe height of the finished block is not affected by thedownward movement ofrthe' exterior mold'62. i

1 When the desired degree of tamping or compaction ".has been achieved, the vibrator 170 is stopped and the press plate 144 is removed from the mold 42. The press frame or member'122, which in turn is connected to the cross bar 108 by means of a plurality of linkages'124.

the'link 128 and the cross bar 108, so as to. bias the link 128 in an outward direction; The tension of the springs 112 is transmitted to'the rods Asshown, each linkage 124 is of the toggle type and thus q by means of the rods 110, the cross bar 108, the linkages 124, and the cross member 122. Thus, the springs 112 exert a'downward pull upon the ejector frame 22.

plate 144 ismove'd to its laterally retracted position, as

shown in FIG. 6. The concrete block is finished at this point but needs to be ejected from the mold 42. In preparation for such ejection, the exterior mold 62 is covered witha pallet 172 adapted to support the finished block after it is ejected from the mold. The pallet 172 is placed on the exterior mold in an inverted position, as shown to advantage in FIG. 6. p a

Hooks 174 are provided to retain the pallet 172. In the illustrated construction, the hooks 174 are formed on the ends of arms 176 which are pivotally mounted on lugs or brackets 17 8 secured to the slidable guide bars 110. Spring's'180 may be-employed to bias thearms 176 against the pallet 172. I 7

Next, the subframe 40 is rotated through substantially 180 degrees soasto invert the mold 42 into the position shown in FIG. 7, in which the pallet.172 is beneath the mold 42. It will be understood thatthe hooks 174 retain thepallet 172 against the block 42-While it is being inverted and while the blockis ejected from the mold. The

This pull, is transmitted to the exterior mold 62' by the I lugs 96'thereon. The pull of the springs 112 is resisted by the force of the compression springs '80 which bias the exterior mold 62 upwardly. I

' As shown in FIG. '4, the mold 42 is adapted to receive a charge'of wet concrete 140. A press 142 is provided to apply pressure to the concrete in the mold 42. The illustrated press 142 comprises a heavy rigid plate 144 adapted to cover the upper side of the exterior mold 62. The plate 144 is adapted to be pressed downwardly by means of a hydraulic or pneumatic cylinder or jack 146 mounted on a trolley frame 148. A piston is To eject the concrete block 20 from the mold 42, the

fluid power cylinder 102 is actuated soas to move the piston 10.4 downwardly in the cylinder 102 :(FIG. 8). In

I this way, the cross bar 108 and-the guide rods 110 are moved downwardly relative to the subframe 40. The downward movement of the cross bar 108 is transmitted to the ejector frame 92 by meansof the linkages 124 and the rods1120. In this way, the block 20 is moved downwardly with the cross bar 108 and the guide rods 110.

, The downward movement of the ejector frame 92 and the block 20 separates the block from the tapered side wall 64 of the interior mold 60. This separation is easily effected because of the tapering shape of the side wall 64. The lid or plate 66 remains in engagement with the block 20 until the heads 71 on the shorter pins 68 engage the lugs 70. The lid 66 is then progressively peeled away from the block 20 until finally the heads 72 on the longer pins 69 engage the lugs 70, whereupon the lid 66 is pulled away completely from the block 2% The progressive removal of the lid 66 prevents the formation of a vacuum or suction between the lid 66 and the lower wall portion of the block 20.

For a short distance, the exterior mold 62 travels downwardly with the ejector frame 92. However, the heads 86 on the stop rods 84 limit the extent to which the exterior mold 62 may move downwardly relative to the subframe 40. When the lugs 82 engage the heads 86, the downward movement of the exterior mold 62 is arrested, whereupon the ejector frame 92 pushes the block 26 out of the exterior mold 62, until the block 26 is completely ejected from the exterior mold 62.

The ejection cylinder 162 is actuated until the pallet 172 is deposited upon the floor, as shown in FIG. 8. A short distance before the pallet 172 engages the floor, the movement of the ejector frame 92 is arrested by the actuation of the toggle linkages 124. Such actuation takes place when the crank arms 132 engage upwardly projecting abutments 2130 on the subframe 40. The resulting rotation of the cranks 132 and the links 128 and 126 shortens the linkages 124, as shown in FIG. 8, so as to arrest the downward movement of the ejector frame 92. In this way, the block 20 may be separated from the frame 92 before the pallet 172 is deposited on the floor.

FIG. 8 represents the final position of the machine. In order that another block may be produced, the machine is returned to its initial position, as shown in FIG. 3. Thus, the hooks 174 are released from the pallet and the fluid pressure in the cylinder 102 is released so that the springs 112 will return the guide rods 11% upwardly to their initial position. Finally, the subframe 40' is rotated through 180 degrees to its initial position.

The entire machine may now be rolled along the floor.

from its position astride the finished block 20 to -a positionin which another block may be molded. In this way, it is not necessary to disturb the freshly molded block until it has hardened suflicicntly to permit it to be removed from the pallet.

It will be appreciated that the illustrated machine is remarkably simple and economical in construction yet is efiicient and easy to :operate. The block is molded in an inverted position and then is turned over so as to facilitate the ejection of the block from the mold. This mode of operation is particularly advantageous for the molding of blocks in the form of open rectangular boxes, of the type shown in FIG. 2. The present machine is capable of molding such blocks with uniformly high quality.

It will be understood that various modifications, alternativeconstructions and equivalents may be employed, without departing from the true spirit and scope of the present invention, as exemplified in the foregoingdescription and defined in the following claims.

I claim:

1. In a machine for molding a concrete product,

the combination comprising a supporting frame,

a mold having an exterior mold part and an interior mold part,

first spring means mounting said interior mold part on said frame,

second spring means mounting said exterior mold part on said frame,

an ejector member movable between said exterior and interior mold parts and forming the bottom of said mold,

resilient means exerting a downward biasing force on said ejector member,

stop means on said exterior mold part limiting downward movement of said ejector member and transmitting said downward force to said exterior mold part,

means for moving said ejector member between said exterior and interior mold parts for ejecting concrete products therefrom,

and additional stop means limiting upward movement of said exterior mold part relative to said frame so as to separate said exterior mold part from the concrete product when said ejector member is moved between said exterior and interior mold part-s.

2. In a machine for molding a concrete product,

the combination comprising a frame,

a mold having an exterior mold part and an interior mold part,

first spring means connecting said interior mold part to said frame,

second spring means connecting said exterior mold part to said frame,

means for turning said frame to invert said mold,

an ejector member movable between said exterior and interior mold parts and forming the bottom of said mold when said mold is in its upright position,

resilient means for exerting a biasing force on said ejector member,

said force being directed downwardly when said mold is upright,

stop means on said exterior mold part limiting downward movement of said ejector member and transmitting said biasing force to said exterior mold part,

said biasing force being resisted by said second spring means,

means for moving said ejector member downwardly when said mold is inverted, for ejecting concrete products from said mold,

said first spring means resisting downward movement of said interior mold part for separating said interior mold part from the concrete product,

and additional stop means for limiting downward movement of said exterior mold part when said mold is inverted so as to separate said exterior mold part from the concrete products. 1

3. In a machine for molding a concrete product,

the combination comprising a main frame,

a subr'rame, a mold mounted on said subframe for receiving a charge of concrete to be molded into a concrete product, means mounting said subframe on said main frame for rotation to invert said subframe and said mold,

said mold comprising an interior mold part and an exterior mold part,

an ejector member movable between said interior and exterior mold parts and forming the bottom of said mold when said mold is in its upright position,

a slide member slidably mounted on said subframe,

a pallet for covering said mold,

means connected to said slide member for disengageably connecting said pallet thereto,

means for moving said slide member downwardly when said subframe and said mold are inverted,

collapsible linkage means connectedbetween said slide member and said ejector member for initially'moving said ejector member downwardly between said interior and exterior mold parts to eject the concrete product from said mold,

said collapsible linkage means being movable between an initial position and a shortened position in which said linkage means is shortened relative to its length in said initial position,

and means operable by continued downward movement of said slide member for collapsing said linkage means to said shortened position and thereby separating said ejector member from the concrete product lwhile the concrete product is supported on said pal- "a slide member, 7

means connected to said slide 4. In amachine for molding a concrete product, I r

the combination comprising a main frame,

a subfrar'ne," I a r I a mold mounted on said subframe for receiving a charge. of. concrete to be molded .into a concrete product, a

nieansrnounting said subframe rotation to invert said subframe and said mold,

said mold comprising an interior mold'part and an exterior mold part, f

an ejector member movable'between said interior and exterior mold parts and forming the bottom of said mold when said mold is in its upright position, j

a slide member slidably mounted on said subframe,

a pallet for covering said mold,

means connected to said slide member for disengage ably connecting said pallet thereto, 2

means for moving said slide member downwardly when said subframe and said mold are inverted,

collapsibletoggle linkage means connected between said slide member and said ejector member for initially moving said ,ejectormember downwardly between said interior and exterior mold parts to eject the of said slide member forcollapsing said toggle linkage means to said shortened position and thereby separating said ejector member from the concrete product while the concrete product-is supported on said pallet. 1 a 5 5. In a machine for molding a concrete product, the combination comprising a mold having an interior mold 'part and an exterior mold part,

an ejector member movable between said interior and exterior mold parts, i

a pallet for covering said mold,

means connected to said slidejme'mber for disengageably connecting said pallet thereto, I

collapsible linkage means connected between said slide member and said ejector member,

said collapsible linkage means being movable between an initial-position and a shortened position in which said linkage means is shortened relative to its length 7 in said initial position,

means for moving said 'slide member relative to said mold for ejecting the concrete product from said pallet,

'and means for collapsing said linkage means to said shortened position in response to continued movement of said slide member for separating the ejector member from the concrete product while the product remains supported on said'pallet. I 6. In a machine for molding a concrete product, 1 the combination comprising a mold having an interior mold part and an exterior mold part, an ejectormember movable between said interior and exterior mold parts, 1 a pallet forcovering said mold, a slide member, 7 p 1 member for disengageably connecting said pallet thereto,

' collapsible toggle linkage means connected between said slide member and said ejector member,

' said'collapsible' toggle linkage means being movable on said main frame for and means operable bycontinued downward movement and means for moving said between an initial position and a shortenediposition in which said: linkage means is shortened relative to its length in said initial position, 1

means for moving said slide member relative to said mold forejecting the concrete product from said mold while the product is maintained against said pallet, 2

and means to saidshortened position for collapsing said toggle linkage means in response to continued movement of said'slide member for separating the ejector member from'the concrete product while the 'productremains supported. on said pallet. 1

7. In a machine' f-or molding a concrete product,

the combination comprising a frame,

I a mold having an exterior mold part and an interior mold part, 1 V

' a first spring means connecting said interior mold part to saidframe,

a second spring means connecting said exterior mold part to. said frame, 5

7 means for turning said frame to invert said mold,

stop means for limiting downward movement of said 7 1 ejector member relative to said exterior mold part and transmitting, saidbiasing force to said exterior mold part,

' said biasing force being resisted by said second spring mounting,

ejector member downwardly when said mold is inverted for ejecting the V concrete product from said mold, 5

said first spring means resisting downward movement of said'interior mold part for separating said interior mold part from the concrete product,

said second spring means limiting downward movement, of said exterior mold part when said'mold is invertedlso as to separate said exterior mold part from the concrete product.

References Cited by the Examiner 'UNITED STATES PATENTS I I 6/12 Pauly 25-120 2,227,756 1/41 ,Kirkham 25- 41.7 2,235,440 3/41 ackerttfl; 25-41 2,298,446 10/42 White 22-41 2,470,577 5/49 ,Shepeck 25 2,512,117 6/50 Sims '25-41 2,529,066 11/50 Annas 25-41 2,686,345 8/54 Young 22-35 2,805,462 9/57 Chandler et al. 25-130 2,807,071 9/57 Francis et al. 25-,130 3,011,241 12/61 Fry etal. 25 41.7

' FOREIGN PATENTS- 605,013 11/34 Germany. 463,868 4/37 Great Britain.

WILLIAM J. STEPHENSON, Primary Examiner. ROBERT F. WHITE, Examiner. 

1. IN A MACHINE FOR MOLDING A CONCRETE PRODUCT THE COMBINATION COMPRISING A SUPPORTING FRAME, A MOLD HAVING AN EXTERIOR MOLD PART AND AN INTERIOR MOLD PART, FIRST SPRING MEANS MOUNTING SAID INTERIOR MOLD PART SAID FRAME, SECOND SPRING MEANS MOUNTING SAID EXTERIOR MOLD PART ON SAID FRAME, AN EJECTOR MEMBER MOVABLE BETWEEN SAID EXTERIOR AND INTERIOR MOLD PARTS AND FORMING THE BOTTOM OF SAID MOLD, RESILIENT MEANS EXERTING A DOWNWARD BIASING FORCE ON SAID EJECTOR MEMBER, STOP MEANS ON SAID EXTERIOR MOLD PART LIMITING DOWNWARD MOVEMENT OF SAID EJECTOR MEMBER AND TRANSMITTING SAID DOWNWARD FORCE TO SAID EXTERIOR MOLD PART, MEANS FOR MOVING SAID EJECTOR MEMBER BETWEEN SAID EXTERIOR AND INTERIOR MOLD PARTS FOR EJECTING CONCRETE PRODUCTS THEREFROM, AND ADDITIONAL STOP MEANS LIMITING UPWARD MOVEMENT OF SAID EXTERIOR MOLD PART RELATIVE TO SAID FRAME SO AS TO SEPARATE SAID EXTERIOR MOLD PART FROM THE CONCRETE PRODUCT WHEN SAID EJECTOR MEMBER IS MOVED BETWEEN SAID EXTERIOR AND INTERIOR MOLD PARTS. 